It's a rather old-fashioned style of tokenization. In the 1980s this was common, I think. But, as noted in another comment, it doesn't work that well for languages with a richer morphology, or compounding. It's a very "English" approach.
However, even though the approach is “old fashioned” it’s still widely used for English. I’m not sure there is a universal approach that semantic search could use that would be both fast and accurate?
At the end of the day people choose a tokenizer that matches their language.
I will update the article to make all this clearer though!